It's important to differentiate between G32 - bed leveling (auto or manual) and G29 (mesh compensation - mesh creation - mesh loading)
Both require setting the Z=0 Datum using G30.
G32 (bed leveling) should be followed by G30.
G29 (mesh creation or loading) should be preceded by G30.
On a machine that allows auto bed leveling you will likely use G32 (bed leveling) followed by G30 (setting the Z=0 Datum) then G29 S1 (mesh loading).
In that case the G30 proceeding the G29 satisfies the need to follow G32 by G30.
The reason for G30 after G32 is that the leveling process can change the Z position of Z=0 - doing the G30 resets the Z=0 Datum correctly.
Hope that clarifies rather than confuses.
Frederick